The most common use of plastic piping is in plumbing. It's lighter and cheaper than metal piping. Rubberized piping can be considered as garden hose piping.
plastic piping has one main advantage and that is that it doesn't rust over time
Copper or plastic piping
Copper, although plastic piping is preferred nowadays.
Lead, plastic. various ferrous and non ferrous metals and glass piping
The formal name of the orange plastic natural gas piping used in the 1970s is Polyethylene (PE) pipe. These pipes were primarily made of high-density polyethylene (HDPE) material and were commonly used for natural gas distribution due to their flexibility and corrosion resistance.
Mercury is not used in piping.
HDPE stands for High-density polyethylene, which is made from petroleum. It is a plastic used in many water bottles, plastic bags, and corrosive-safe piping.
To make a piping bag nozzle at home, you can cut a small hole in the corner of a plastic sandwich bag or use a sturdy plastic bottle with a small opening. Fill the bag or bottle with your desired icing or frosting, then twist the top of the bag or bottle to push the icing out through the hole. This makeshift nozzle can be used for basic piping tasks in baking and decorating.
Any kind of non plastic piping will do (namely copper or galvanised for water and uPVC for Waste). Unless of course this cannot be done due to high theft of metallic piping.
Utility pipes made out of Poly Vinyl Chloride (PVC) a plastic.
As far as I know, for underground piping use plastic, for above ground steel or copper. That is the practice in the UK, but I don't know about the US. I would be surprised if it is different. We did have underground steel pipes but these are now being replaced with plastic and all new is plastic (underground)